29 covers written up on exhibit pages, begins with "Liverpool & New York & Phild'a Steamship Co." cornercard on backflap of 1857 cover, continues with manuscript "10" and "20" on "Phila. 5Cts. Paid" octagon (Clarke 528b, 528c), 1865 incoming cover from Cuba "p Stars & Stripes" with "20" rate handstamp (earliest reported Philadelphia inbound steamship rate), pair of January 27, 1866 covers with first set of steamship markings (separate "Steam" "Ship") rated "10" and "20", the latter the unique multiple rate (Clarke 645a, 645b), various examples of the second steamship markings (Clarke 646, 649) including unrecorded use of 20c in blue, blue "Phil'a Unpaid" on 10c and 20c letters from Cuba to Paris, third set of steamship markings including the unique example of the "Steamship 20" handstamp (Clarke 647, 650), fourth set of steamship markings (Clarke 648, 651), and more, generally very fine, an extraordinary collection, extensively researched with a number of items ex-Wierenga, impossible to duplicate and deserving of a thorough viewing